1. Field of the Invention
The present disclosure relates generally to fiber cement manufacturing, and more particularly, to systems and methods for reducing water usage in fiber cement manufacturing processes.
2. Description of the Related Art
Commercial fiber reinforced cementitious shaped articles, such as fiber cement building panels and exterior sidings, are usually manufactured using large scale cementitious forming processes. These large scale operations, such as industrial-size Hatschek process, typically require the use of millions of gallons of water as a process aid. While some efforts have been made to recycle and reuse the large volume of process water in fiber cement manufacturing, the efforts have been largely limited to installing filtration systems to remove particulates from the spent water or adjusting pH of the water for discharge. The recycled process water typically has high alkali content because cement continues to leach alkali during the cementitious forming process. As such, when the process water is reused, the alkali metal ions in the water can accumulate and detrimentally affect product properties.
Ion exchange systems have been used to treat water in both industrial and household applications to remove ions from water. For example, ion exchangers have been used in household water purification systems and in industrial applications such as desalination of sea water and removal of metals from plating solutions in semiconductor processing. However, conventional ion exchange systems are not equipped to handle, treat, and maintain a closed-loop circulation of the extremely high volume of process water with complex chemical make-up required in fiber cement manufacturing. Moreover, conventional ion exchange systems are not designed to treat extremely complex spent water from cementitious forming processes in a manner such that the treated water can provide enhanced functional properties to the final product. In view of the foregoing, there remains a need for improved systems and methods for reducing water usage in large scale fiber cement manufacturing processes.